We communicate the finding of a subcutaneous neoplasia in a female specimen of the toad Melanophryniscus montevidensis (Bufonidae) from Uruguay. The lesion extended from the cephalic to the abdominal region, and both gross and microscopic features were typical of lipomas. This is to our knowledge the fourth case reported in amphibians.Asociación Herpetológica Argentin

Borteiro, Claudio

Kolenc, Francisco

Machín, Victoria

Rossini, Emilia

Verdes, José Manuel

Cuadernos de Herpetología

English

SEDICI - Repositorio de la UNLP

Nota
133
Author for correspondence: emilis_2@hotmail.com
Lipomatous tumour in the endangered toad Melanophryniscus 
montevidensis (Anura: Bufonidae) from Uruguay
Emilia Rossini1, Victoria Machín1, Claudio Borteiro1,2, Francisco Kolenc2, José Manuel Verdes1
1 Departamento de Patología, Facultad de Veterinaria, Universidad de la República. Lasplaces 1550, Monte-
video 11600, Uruguay.
2 Sección Herpetología, Museo Nacional de Historia Natural, 25 de Mayo 582, Montevideo 11000, Uruguay.
Cuad. herpetol. 32(2): 133-135 (2018)
The study of skin-related tumours in amphibians 
constitutes a relevant issue in amphibian oncology 
(Balls and Clothier, 1974; Asashima et al., 1987). 
Several types of neoplasia can affect the skin and sub-
cutaneous tissue of these vertebrates, like papillomas, 
adenomas, adenocarcinomas, squamous cell carci-
noma, chromatophoromas and also mesenchymatic 
tumours including lipomas (Schlumberger and 
Lucké, 1948; Balls, 1962; Berger et al., 2004). Sponta-
neous tumours in wild amphibians are rarely repor-
ted, except for pollution-induced melanophoromas 
in salamanders of the genus Ambystoma (Rose and 
Harshbarger, 1977). In this note we communicate 
the finding of a lipomatous tumour in Melanophry-
niscus montevidensis (Bufonidae) in Uruguay. This 
toad is native to sandy coastal areas and associated 
lowland grasslands in southern Uruguay and eastern 
Argentina in Buenos Aires Province, as well as hilly 
environments of the latter, where habitat loss is of 
great concern for amphibians (Kolenc et al., 2009; 
Baldo, in Vaira et al., 2012). 
An adult female of this species with a noticea-
ble mass on the left side of cephalic region and trunk 
was captured in a field trip to Laguna de Rocha, 
Departamento de Rocha, southeastern Uruguay 
(34°38’21 S; 54°12’01 W, 48 m altitude). The toad 
was collected at a temporary pond during a repro-
ductive episode, on February 21, 2018, and measured 
28.3 mm of snout-vent length. It looked otherwise 
healthy, and did not exhibit abnormal behaviours 
or postures. Its condition did not affect normal dis-
placement. In the laboratory it was euthanized by 
cutaneous application of 20% benzocaine gel, and 
fixed with 10% formalin. Permits for capture and 
handling in the laboratory were issued by División 
Fauna – MGAP and Comité de Ética en el Uso de 
Animales of Facultad de Veterinaria, respectively. 
The lesion was dissected, and routinely processed 
for histological evaluation with hematoxylin and 
eosin staining (H&E); voucher number 18/225, in 
Departamento de Patología, Facultad de Veterinaria, 
Universidad de la República, Montevideo, Uruguay 
(FVET-UdelaR).
The protruding area that called our attention 
was more evident just posterior to the eye. Dissec-
tion of this lesion under a stereoscopic microscope 
showed a circumscribed structure of fat-like tissue 
and whitish colour, extending subcutaneously over 
the flank up to the posterior part of the abdomen 
(Fig. 1). At histological examination it consisted of a 
lipomatous tumour with a thin fibrous capsule. The 
capsule presented several fibrous attachments to the 
dermis and contiguous musculature (Fig. 2 A). The 
tissue forming the stroma of this neoplasia consisted 
mainly of typical adipocytes with moderate prolife-
ration of blood vessels; some areas presented scat-
tered chromatophores (presumably melanophores) 
and a small extent of fibrous tissue (Fig. 2 B). Both 
gross and microscopic characteristics of the lesion 
correspond to those of lipomas (Hendrick, 2017). 
Recibida:  2 8  A g o s t o  2 0 1 8
Revisada:  2 9  A g o s t o  2 0 1 8
Aceptada:  3 1  A g o s t o  2 0 1 8
Editor  Asociado:  J.  Goldberg
doi:  10.31017/CdH.2018.(2018-020)
ABSTRACT
We communicate the finding of a subcutaneous neoplasia in a female specimen of the toad 
Melanophryniscus montevidensis (Bufonidae) from Uruguay. The lesion extended from the 
cephalic to the abdominal region, and both gross and microscopic features were typical of 
lipomas. This is to our knowledge the fourth case reported in amphibians.
Key Words: Lipoma; Neoplasia; Amphibians
134
E. Rossini et al.  - Lipomatous tumour in Melanophryniscus montevidensis
Lipomas are bening and slow growing tumours 
(Hendrick, 2017), and their presentation in wild 
vertebrates seems to be sporadic. Particularly in 
amphibians there are only three previously published 
case reports, the first one is that of Reichenbach-
Klinke and Elkan (1965) who describe this neoplasia 
associated to the urinary bladder in a toad Bufo 
bufo (Bufonidae). The other two known cases, like 
in the present study, correspond to single and cir-
cumscribed subcutaneous lipomas in Xenopus laevis 
(Pipidae; Balls, 1962) and Melanophryniscus san-
martini (Borteiro et al., 2017). In these two reports 
the lipomas were approximately ovoid and relatively 
small masses located in the dorsum. As a difference, 
the lipoma in the present case largely extended over 
the flank. Similarly to the case in M. sanmartini, 
chromatophore cells were present but scarce.
Although the pathology of native toads of the 
genus Melanophryniscus has been scarcely studied 
(Langone and Maneyro, 1999; Borteiro et al., 2017), 
the frequency of neoplasias seems to be low (Bor-
teiro, 2016). However, it is noteworthy that three of 
the four cases reported in amphibians correspond 
to bufonid species. Further data is needed to assess 
if bufonid toads present a particular predisposition 
to exhibit lipomas. Although benign, we are un-
aware about the possible deleterious effects of these 
expansile neoplasias by diminishing fitness in wild 
amphibians.
Acknowledgements
We thank Victoria Yozzi and Mayra Severo for 
their support at the laboratory of Departamento de 
Patología.
Literature cited
Asashima, M.; Oinuma, T. & Meyer-Rochow, V.B. 1987. Tumors 
in Amphibia. Zoological Science 4: 411-425.
Balls, M. 1962. Spontaneous neoplasms in Amphibia: a review and 
descriptions of six newcases. Cancer Research 22: 1142-1154.
Figure 1. Lipoma in Melanophryniscus montevidensis. Arrows on the left indicate approximate boundaries of the tumour in the sub-
cutaneous tissue of the cephalic region, which are evident externally; vertical one corresponds to its posterior limits.
135
Cuad. herpetol. 32 (2): 133-135 (2018)
Balls, M. & Clothier, R.H. 1974. Spontaneous tumors in 
Amphibia. Oncology 29: 501-519.
Berger, L.; Speare, R. & Middleton, D. 2004. A squamous cell 
carcinoma and an adenocarcinoma in Australian treefrogs. 
Australian Veterinary Journal 82: 96-98.
Borteiro, C. 2016. Enfermedades de la piel en anfibios de 
Uruguay y sureste de Brasil: nuevos diagnósticos y posibles 
efectos. PhD Thesis, PEDECIBA - Facultad de Ciencias, 
Universidad de la República, Montevideo.
Borteiro, C., Kolenc, F., Verdes, J.M., Martínez Debat, C. 
& Ubilla, M. 2017. Subcutaneous lipoma in the toad 
Melanophryniscus sanmartini, third case in amphibians. 
Herpetology Notes 10: 709-711.
Hendrick, M.J. 2017. Mesenchymal tumors of the skin and soft 
tissue: 142-175. In: Meuten, D.J. (ed.) Tumors in domestic 
animals. 5th ed., John Wiley & Sons, Ames, Iowa.
Kolenc, F.; Borteiro, C.; Baldo, D.; Ferraro, D. & Prigioni, C. 2009. 
The tadpoles and advertisement calls of Pleurodema bibroni 
Tschudi and Pleurodema kriegi (Müller), with notes on their 
geographic distribution and conservation status (Amphibia, 
Anura, Leiuperidae). Zootaxa 1969: 1-35.
Langone, J.A. & Maneyro, R. 1999. Malformaciones en los 
miembros en ejemplares del género Melanophryniscus de 
poblaciones uruguayas. Publicación Extra, Museo Nacional 
de Historia Natural (Montevideo) 50: 75.
Reichenbach-Klinke, H. & Elkan, E. 1965. The principal diseases 
of lower vertebrates. Academic Press, London & New York.
Rose, F.L. & Harshbarger, J.C. 1977. Neoplastic and possibly 
related skin lesions in neotenic Tiger salamanders from a 
sewage lagoon. Science 197: 315-317.
Schlumberger, H.H. & Lucké, B. 1948. Tumors of fishes, 
amphibians and reptiles. Cancer Research 8: 657-754.
Vaira, M.; Akmentins, M.S.; Attademo, M.; Baldo, D.; Barrasso, 
D.; Barrionuevo, S.; Basso, N.; Blotto, B.; Cairo, S.; Cajade, 
R.; Céspedez, J.; Corbalán, V.; Chilote, P.; Duré, M.; Falcione, 
C.; Ferraro, D.; Gutiérrez, F.R.; Ingaramo, M.R.; Junges, C.; 
Lajmanovich, R.; Lescano, J.N.; Marangoni, F.; Martinazzo, 
L.; Marti, R.; Moreno, L.; Natale, G.S.; Pérez Iglesias, J.M.; 
Peltzer, P.; Quiroga, L.; Rosset, S.; Sanabria, E.; Sánchez, L.; 
Schaefer, E.; Úbeda, C.; Zaracho, V. 2012. Categorización 
del estado de conservación de los anfibios de la República 
Argentina. Cuadernos de Herpetología 26(Supl. 1): 131-159.
Figure 2. Subcutaneous lipoma in Melanophryniscus montevi-
densis. A, panoramic view of the tumour and the fibrous capsule 
containing it; histological section at the thoracic level (H&E, 
100X). Dashed square corresponds to next figure. B, lipoma 
(L) at higher magnification (H&E, 400X). Other abbreviations: 
bv, blood vessel; c, chromatophores; d, dermis; e, epidermis; fc, 
fibrous capsule; gg, granular gland.
© 2018 por los autores, licencia otorgada a la Asociación Herpetológica Argentina. 
Este artículo es de acceso abierto y distribuido bajo los términos y condiciones de 
una licencia Atribución-No Comercial 2.5 Argentina de Creative Commons. Para ver 
una copia de esta licencia, visite http://creativecommons.org/licenses/by-nc/2.5/ar/



Lipomatous tumour in the endangered toad <i>Melanophryniscus montevidensis</i>(Anura: Bufonidae) from Uruguay

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Nota133Author for correspondence: emilis_2@hotmail.comLipomatous tumour in the endangered toad Melanophryniscus montevidensis (Anura: Bufonidae) from UruguayEmilia Rossini1, Victoria Machín1, Claudio Borteiro1,2, Francisco Kolenc2, José Manuel Verdes11 Departamento de Patología, Facultad de Veterinaria, Universidad de la República. Lasplaces 1550, Monte-video 11600, Uruguay.2 Sección Herpetología, Museo Nacional de Historia Natural, 25 de Mayo 582, Montevideo 11000, Uruguay.Cuad. herpetol. 32(2): 133-135 (2018)The study of skin-related tumours in amphibians constitutes a relevant issue in amphibian oncology (Balls and Clothier, 1974; Asashima et al., 1987). Several types of neoplasia can affect the skin and sub-cutaneous tissue of these vertebrates, like papillomas, adenomas, adenocarcinomas, squamous cell carci-noma, chromatophoromas and also mesenchymatic tumours including lipomas (Schlumberger and Lucké, 1948; Balls, 1962; Berger et al., 2004). Sponta-neous tumours in wild amphibians are rarely repor-ted, except for pollution-induced melanophoromas in salamanders of the genus Ambystoma (Rose and Harshbarger, 1977). In this note we communicate the finding of a lipomatous tumour in Melanophry-niscus montevidensis (Bufonidae) in Uruguay. This toad is native to sandy coastal areas and associated lowland grasslands in southern Uruguay and eastern Argentina in Buenos Aires Province, as well as hilly environments of the latter, where habitat loss is of great concern for amphibians (Kolenc et al., 2009; Baldo, in Vaira et al., 2012). An adult female of this species with a noticea-ble mass on the left side of cephalic region and trunk was captured in a field trip to Laguna de Rocha, Departamento de Rocha, southeastern Uruguay (34°38’21 S; 54°12’01 W, 48 m altitude). The toad was collected at a temporary pond during a repro-ductive episode, on February 21, 2018, and measured 28.3 mm of snout-vent length. It looked otherwise healthy, and did not exhibit abnormal behaviours or postures. Its condition did not affect normal dis-placement. In the laboratory it was euthanized by cutaneous application of 20% benzocaine gel, and fixed with 10% formalin. Permits for capture and handling in the laboratory were issued by División Fauna – MGAP and Comité de Ética en el Uso de Animales of Facultad de Veterinaria, respectively. The lesion was dissected, and routinely processed for histological evaluation with hematoxylin and eosin staining (H&E); voucher number 18/225, in Departamento de Patología, Facultad de Veterinaria, Universidad de la República, Montevideo, Uruguay (FVET-UdelaR).The protruding area that called our attention was more evident just posterior to the eye. Dissec-tion of this lesion under a stereoscopic microscope showed a circumscribed structure of fat-like tissue and whitish colour, extending subcutaneously over the flank up to the posterior part of the abdomen (Fig. 1). At histological examination it consisted of a lipomatous tumour with a thin fibrous capsule. The capsule presented several fibrous attachments to the dermis and contiguous musculature (Fig. 2 A). The tissue forming the stroma of this neoplasia consisted mainly of typical adipocytes with moderate prolife-ration of blood vessels; some areas presented scat-tered chromatophores (presumably melanophores) and a small extent of fibrous tissue (Fig. 2 B). Both gross and microscopic characteristics of the lesion correspond to those of lipomas (Hendrick, 2017). Recibida:  2 8  A g o s t o  2 0 1 8Revisada:  2 9  A g o s t o  2 0 1 8Aceptada:  3 1  A g o s t o  2 0 1 8Editor  Asociado:  J.  Goldbergdoi:  10.31017/CdH.2018.(2018-020)ABSTRACTWe communicate the finding of a subcutaneous neoplasia in a female specimen of the toad Melanophryniscus montevidensis (Bufonidae) from Uruguay. The lesion extended from the cephalic to the abdominal region, and both gross and microscopic features were typical of lipomas. This is to our knowledge the fourth case reported in amphibians.Key Words: Lipoma; Neoplasia; Amphibians134E. Rossini et al.  - Lipomatous tumour in Melanophryniscus montevidensisLipomas are bening and slow growing tumours (Hendrick, 2017), and their presentation in wild vertebrates seems to be sporadic. Particularly in amphibians there are only three previously published case reports, the first one is that of Reichenbach-Klinke and Elkan (1965) who describe this neoplasia associated to the urinary bladder in a toad Bufo bufo (Bufonidae). The other two known cases, like in the present study, correspond to single and cir-cumscribed subcutaneous lipomas in Xenopus laevis (Pipidae; Balls, 1962) and Melanophryniscus san-martini (Borteiro et al., 2017). In these two reports the lipomas were approximately ovoid and relatively small masses located in the dorsum. As a difference, the lipoma in the present case largely extended over the flank. Similarly to the case in M. sanmartini, chromatophore cells were present but scarce.Although the pathology of native toads of the genus Melanophryniscus has been scarcely studied (Langone and Maneyro, 1999; Borteiro et al., 2017), the frequency of neoplasias seems to be low (Bor-teiro, 2016). However, it is noteworthy that three of the four cases reported in amphibians correspond to bufonid species. Further data is needed to assess if bufonid toads present a particular predisposition to exhibit lipomas. Although benign, we are un-aware about the possible deleterious effects of these expansile neoplasias by diminishing fitness in wild amphibians.AcknowledgementsWe thank Victoria Yozzi and Mayra Severo for their support at the laboratory of Departamento de Patología.Literature citedAsashima, M.; Oinuma, T. & Meyer-Rochow, V.B. 1987. Tumors in Amphibia. Zoological Science 4: 411-425.Balls, M. 1962. Spontaneous neoplasms in Amphibia: a review and descriptions of six newcases. Cancer Research 22: 1142-1154.Figure 1. Lipoma in Melanophryniscus montevidensis. Arrows on the left indicate approximate boundaries of the tumour in the sub-cutaneous tissue of the cephalic region, which are evident externally; vertical one corresponds to its posterior limits.135Cuad. herpetol. 32 (2): 133-135 (2018)Balls, M. & Clothier, R.H. 1974. Spontaneous tumors in Amphibia. Oncology 29: 501-519.Berger, L.; Speare, R. & Middleton, D. 2004. A squamous cell carcinoma and an adenocarcinoma in Australian treefrogs. Australian Veterinary Journal 82: 96-98.Borteiro, C. 2016. Enfermedades de la piel en anfibios de Uruguay y sureste de Brasil: nuevos diagnósticos y posibles efectos. PhD Thesis, PEDECIBA - Facultad de Ciencias, Universidad de la República, Montevideo.Borteiro, C., Kolenc, F., Verdes, J.M., Martínez Debat, C. & Ubilla, M. 2017. Subcutaneous lipoma in the toad Melanophryniscus sanmartini, third case in amphibians. Herpetology Notes 10: 709-711.Hendrick, M.J. 2017. Mesenchymal tumors of the skin and soft tissue: 142-175. In: Meuten, D.J. (ed.) Tumors in domestic animals. 5th ed., John Wiley & Sons, Ames, Iowa.Kolenc, F.; Borteiro, C.; Baldo, D.; Ferraro, D. & Prigioni, C. 2009. The tadpoles and advertisement calls of Pleurodema bibroni Tschudi and Pleurodema kriegi (Müller), with notes on their geographic distribution and conservation status (Amphibia, Anura, Leiuperidae). Zootaxa 1969: 1-35.Langone, J.A. & Maneyro, R. 1999. Malformaciones en los miembros en ejemplares del género Melanophryniscus de poblaciones uruguayas. Publicación Extra, Museo Nacional de Historia Natural (Montevideo) 50: 75.Reichenbach-Klinke, H. & Elkan, E. 1965. The principal diseases of lower vertebrates. Academic Press, London & New York.Rose, F.L. & Harshbarger, J.C. 1977. Neoplastic and possibly related skin lesions in neotenic Tiger salamanders from a sewage lagoon. Science 197: 315-317.Schlumberger, H.H. & Lucké, B. 1948. Tumors of fishes, amphibians and reptiles. Cancer Research 8: 657-754.Vaira, M.; Akmentins, M.S.; Attademo, M.; Baldo, D.; Barrasso, D.; Barrionuevo, S.; Basso, N.; Blotto, B.; Cairo, S.; Cajade, R.; Céspedez, J.; Corbalán, V.; Chilote, P.; Duré, M.; Falcione, C.; Ferraro, D.; Gutiérrez, F.R.; Ingaramo, M.R.; Junges, C.; Lajmanovich, R.; Lescano, J.N.; Marangoni, F.; Martinazzo, L.; Marti, R.; Moreno, L.; Natale, G.S.; Pérez Iglesias, J.M.; Peltzer, P.; Quiroga, L.; Rosset, S.; Sanabria, E.; Sánchez, L.; Schaefer, E.; Úbeda, C.; Zaracho, V. 2012. Categorización del estado de conservación de los anfibios de la República Argentina. Cuadernos de Herpetología 26(Supl. 1): 131-159.Figure 2. Subcutaneous lipoma in Melanophryniscus montevi-densis. A, panoramic view of the tumour and the fibrous capsule containing it; histological section at the thoracic level (H&E, 100X). Dashed square corresponds to next figure. B, lipoma (L) at higher magnification (H&E, 400X). Other abbreviations: bv, blood vessel; c, chromatophores; d, dermis; e, epidermis; fc, fibrous capsule; gg, granular gland.© 2018 por los autores, licencia otorgada a la Asociación Herpetológica Argentina. Este artículo es de acceso abierto y distribuido bajo los términos y condiciones de una licencia Atribución-No Comercial 2.5 Argentina de Creative Commons. Para ver una copia de esta licencia, visite http://creativecommons.org/licenses/by-nc/2.5/ar/

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Lipomatous tumour in the endangered toad <i>Melanophryniscus montevidensis</i>(Anura: Bufonidae) from Uruguay

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